US7762019B2 - Plant protective cover - Google Patents

Plant protective cover Download PDF

Info

Publication number
US7762019B2
US7762019B2 US10/548,104 US54810404A US7762019B2 US 7762019 B2 US7762019 B2 US 7762019B2 US 54810404 A US54810404 A US 54810404A US 7762019 B2 US7762019 B2 US 7762019B2
Authority
US
United States
Prior art keywords
protective cover
transmission
plant protective
cover
plants
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US10/548,104
Other languages
English (en)
Other versions
US20060254136A1 (en
Inventor
Leon Van Rensburg
Tjaart Andries Du Plessis
Horst Seute
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
North West University
Original Assignee
North West University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by North West University filed Critical North West University
Assigned to NORTH-WEST UNIVERSITY reassignment NORTH-WEST UNIVERSITY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DU PLESSIS, TJAART ANDRIES, SEUTE, HORST, VAN RENSBURG, LEON
Publication of US20060254136A1 publication Critical patent/US20060254136A1/en
Application granted granted Critical
Publication of US7762019B2 publication Critical patent/US7762019B2/en
Expired - Fee Related legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
    • A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
    • A01G9/14—Greenhouses
    • A01G9/1438—Covering materials therefor; Materials for protective coverings used for soil and plants, e.g. films, canopies, tunnels or cloches
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
    • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
    • Y02A40/25—Greenhouse technology, e.g. cooling systems therefor

Definitions

  • This invention relates to a plant protective cover, a method of manufacturing a plant protective cover, plants cultivated using the plant protective cover and a method of cultivating plants using such plant protective cover.
  • Known commercially available plant protective covers comprise transparent or opaque thermoplastic flexible films or rigid sheets used for covering plants to protect them from environmental factors such as extreme temperatures, harmful insects, dust, infrared (IR) radiation and ultraviolet (UV) radiation.
  • U.S. Pat. No. 4,895,904 discloses polymer sheets or films for use in the construction of greenhouses.
  • the polymer sheets or films contain additives, which absorb or reflect light in the near IR region, as well as additives for the stabilisation of UV radiation. These sheets are essentially transparent to the photosynthetic active region of the light spectrum.
  • JP 7067 479 discloses a material for enhancing plant growth by manipulating the transmitted light spectrum.
  • the material incorporates additives for screening IR, transmitting visible light and only partially transmitting UV.
  • SmartlightTM and Sun SelectorTM trade marks are sold under the SmartlightTM and Sun SelectorTM trade marks. Photosynthesis strongly depends on the total amount of light that plants receive in the photosynthetic active region with major contributions from blue and red light.
  • the SmartlightTM cover is a photo-selective plant cover that converts part of the UV light to red light, whilst also limiting the transmission of light on the longer end of the wavelength spectrum.
  • the Sun SelectorTM film is a multi-layer photo selective film for use in the construction of greenhouses and tunnel coverings.
  • the Sun SelectorTM film contains IR additives to enable the film to absorb or reflect IR radiation. This film is further stabilised against UV radiation. Maximum light is transmitted in the visible range between 400 nm and 700 nm.
  • the known plant protective covers are primarily aimed at protecting a plant, cultivated underneath the cover, from environmental variables. These covers allow non-selective maximum transmission in the visible light range of the spectrum (400 nm-750 nm). However, they do not provide optimal transmittance spectra in the photosynthetic active region or cater for the specific photosynthetic and photomorphogenic needs of different varieties of plants. This is a disadvantage since different plant varieties respond to different photosynthetic and photomorphogenically active wavelengths of light and the known plant covers do not discriminate selectively between the said different wavelengths nor do they provide optimal transmittance spectra, which favours most plant varieties. The positive effect of the prior art covers on plants is therefore limited.
  • a plant protective cover of a translucent polymeric material including at least one transmission spectrum modifier for minimising the transmission in the ultraviolet range up to 350 nm; and for adjusting the transmission in the visible light range between 350 nm and 750 nm in accordance with photosynthetic and photomorphogenic requirements of plants to be cultivated underneath the plant protective cover, to enhance the growth conditions of such plants.
  • the plant protective cover includes a transmission spectrum modifier for minimising the transmission in the infrared range above 750 nm.
  • the transmission in the visible light range between 350 nm and 750 nm is adjusted by decreasing the transmitted green and yellow wavelengths.
  • the transmission in the visible light range between 350 nm and 750 nm is adjusted by changing the ratio of blue to red wavelengths transmitted towards a 2:3 ratio.
  • the transmission spectrum modifier may be selected from the group consisting of silicates, sodium metaphosphates, alunite, aluminium hydroxide, boron hydroxides, magnesium oxide, copper oxide, black iron oxide, cobalt oxide, coated copper powder, blue cobalt oxide, UV radiation stabilisers, and pigments.
  • the plant protective cover may include additional additives selected from the group consisting of antioxidants, processing aids, anti-dust, and anti-fog agents.
  • the plant protective cover may include between 0.1 and 2.0% of a benzotriazole UV absorber on a mass per mass basis.
  • the plant protective cover includes 0.7% on a mass per mass basis of the benzotriazole UV absorber in the form of 2-(2-hydroxy-3-sec-butyl-5-t-butylphenyl)benzotriazole.
  • the plant protective cover may include between 0.1 and 2.0% of a hindered amine light stabiliser on a mass per mass basis.
  • the plant protective cover includes 0.3% on a mass per mass basis of the hindered amine light stabiliser in the form of dimethyl succinate .w/4-hydroxy-2,2,6,6-tetramethyl-1piperidine ethanol.
  • the plant protective cover may include 0.3% on a mass per mass basis of the hindered amine light stabiliser in the form of poly((6-((1,1,3,3-tetramethylbutyl)amino)-s-triazine-2,4dijil)(2,2,6.6-tetramethyl-4-piperidyl)imino)hexamethylene(2,2,6,6-tetramethyl-4-piperidyl)imino))).
  • the hindered amine light stabiliser in the form of poly((6-((1,1,3,3-tetramethylbutyl)amino)-s-triazine-2,4dijil)(2,2,6.6-tetramethyl-4-piperidyl)imino)hexamethylene(2,2,6,6-tetramethyl-4-piperidyl)imino))).
  • the plant protective cover may include between 0.1 and 2.0% of a phosphite antioxidant on a mass per mass basis.
  • the plant protective cover includes 0.4% on a mass per mass basis of the phosphite antioxidant in the form of tris(2,4-di-t-butylphenyl)phosphite.
  • the plant protective cover may include between 0.1 and 2.0% of a phenolic antioxidant on a mass per mass basis.
  • the plant protective cover includes 0.2% on a mass per mass basis of the phenolic antioxidant stabiliser in the form of 1,3,5-trimethyl-2,4,6-tris(3,5-ditert-butyl-4-hydroxybenzyl)benzene.
  • the plant protective cover may include between 0.1 and 2.0% of a hindered phenolic antioxidant on a mass per mass basis.
  • the plant protective cover includes 0.2% on a mass per mass basis of the hindered phenolic antioxidant In the form of tetrakismethylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane.
  • the plant protective cover may include between 0.05 and 2.0% of a spectrum modifier on a mass per mass basis.
  • the plant protective cover includes 0.1% on a mass per mass basis of the spectrum modifier in the form of chromophtal red BRN.
  • the plant protective cover may include between 1.0 and 3.0% of an IR absorber on a mass per mass basis.
  • the plant protective cover includes 2.0% on a mass per mass basis of the IR absorber in the form of calcium carbonate (52%), magnesium carbonate (42%), silica (5%) and aluminium hydroxide.
  • the polymeric material is a partially cross-linked polymeric thermoplastic material.
  • the partially cross-linked polymeric thermoplastic material is made by subjecting a polymeric thermoplastic starting material, which is capable of being cross-linked by ionising irradiation, to sufficient ionising radiation to cross-link the starting material partially.
  • the plant protective cover may include up to 95% on a mass per mass basis of a radiation pre-crosslinked linear low-density polyethylene having a melt flow index (MFI) from 0.40 to 0.50.
  • MFI melt flow index
  • the cover may be produced in a form selected from the group consisting of a mono film, a multi-layer laminate film, a rigid sheet, and a woven or knitted net.
  • the polymeric material may be selected from the group consisting of polyethylenes and co-polymers of polyethylene, such as poly(ethylene-co-ethyl vinyl acetate), and polyvinyl chloride (PVC).
  • the polymeric material may be selected from the group consisting of polyethylene, polyvinyl chloride (PVC), polycarbonate (PC), polyethylene terephthalate (PET), and glass reinforced polyesters (GRP).
  • PVC polyvinyl chloride
  • PC polycarbonate
  • PET polyethylene terephthalate
  • GRP glass reinforced polyesters
  • the polymeric material may be selected from the group consisting of fibrous polyethylenes, polyamides, and polyesters.
  • a method of manufacturing a plant protective cover including the steps of providing a translucent polymeric material; and incorporating in the material at least one transmission spectrum modifier for minimising the transmission in the ultraviolet range up to 350 nm; and for adjusting the transmission in the visible light range between 350 nm and 750 nm in accordance with photosynthetic and photomorphogenic requirements of plants to be cultivated underneath the plant protective cover, to enhance the growth conditions of such plants.
  • the method includes the further step of incorporating in the cover a transmission spectrum modifier for minimising the transmission in the infrared range above 750 nm.
  • the transmission in the visible light range between 350 nm and 750 nm is adjusted by decreasing the transmitted green and yellow wavelengths.
  • the transmission in the visible light range between 350 nm and 750 nm is adjusted by changing the ratio of blue to red wavelengths transmitted towards a 2:3 ratio.
  • the step of incorporating transmission spectrum modifiers may yet further include the step of selecting the transmission spectrum modifiers from the group consisting of silicates, sodium metaphosphates, alunite, aluminium hydroxide, boron hydroxides, magnesium oxide, copper oxide, black iron oxide, cobalt oxide, coated copper powder, blue cobalt oxide UV radiation stabilisers, and pigments.
  • the method may include the further step of incorporating in the cover additional additives selected from the group consisting of antioxidants, processing aids, anti-dust, and anti-fog agents.
  • the method may include the step of incorporating in the cover between 0.1 and 2.0% of a benzotriazole UV absorber on a mass per mass basis.
  • the method includes the step of incorporating in the cover 0.7% on a mass per mass basis of the benzotriazole UV absorber in the form of 2-(2-hydroxy-3-sec-butyl-5-t-butylphenyl)benzotriazole.
  • the method may include the step of incorporating in the cover between 0.1 and 2.0% of a hindered amine light stabiliser on a mass per mass basis.
  • the method includes the step of incorporating in the cover 0.3% on a mass per mass basis of the hindered amine light stabiliser in the form of dimethyl succinate .w/4-hydroxy-2,2,6,6-tetramethyl-1piperidine ethanol.
  • the method may include the step of incorporating in the cover 0.3% on a mass per mass basis of the hindered amine light stabiliser in the form of poly((6-((1,1,3,3-tetramethylbutyl)amino)-s-triazine-2,4dijil)(2,2,6.6-tetramethyl-4-piperidyl)imino)hexamethylene(2,2,6,6-tetramethyl-4-piperidyl) imino))).
  • the method may include the step of incorporating in the cover between 0.1 and 2.0% of a phosphite antioxidant on a mass per mass basis.
  • the method includes the step of incorporating in the cover 0.4% on a mass per mass basis of the phosphite antioxidant in the form of tris(2,4-di-t-butylphenyl)phosphite.
  • the method may include the step of incorporating in the cover between 0.1 and 2.0% of a phenolic antioxidant on a mass per mass basis.
  • the method includes the step of incorporating in the cover 0.2% on a mass per mass basis of the phenolic antioxidant stabiliser in the form of 1,3,5-trimethyl-2,4,6-tris(3,5-ditert-butyl-4-hydroxybenzyl)benzene.
  • the method may include the step of incorporating in the cover between 0.1 and 2.0% of a hindered phenolic antioxidant on a mass per mass basis.
  • the method includes the step of incorporating in the cover 0.2% on a mass per mass basis of the hindered phenolic antioxidant in the form of tetrakismethylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)methane.
  • the method may include the step of incorporating in the cover between 0.05 and 2.0% of a spectrum modifier on a mass per mass basis.
  • the method may include the step of incorporating in the cover 0.1% on a mass per mass basis of the spectrum modifier in the form of chromophtal red BRN.
  • the method may include the step of incorporating in the cover between 1.0 and 3.0% of an IR absorber on a mass per mass basis.
  • the method includes the step of incorporating in the cover 2.0% on a mass per mass basis of the IR absorber in the form of calcium carbonate (52%), magnesium carbonate (42%), silica (5%) and aluminium hydroxide.
  • the polymeric material is a partially cross-linked polymeric thermoplastic material.
  • the partially cross-linked polymeric thermoplastic material may be made by subjecting a polymeric thermoplastic starting material, which is capable of being cross-linked by ionising irradiation, to sufficient ionising radiation to cross-link the starting material partially.
  • the method may include the step of incorporating in the cover up to 95% on a mass per mass basis of a radiation pre-crosslinked linear low-density polyethylene having a melt flow index (MFI) from 0.40 to 0.50.
  • MFI melt flow index
  • the additional additives and transmission spectrum modifiers may be incorporated in one or more films extruded in a form selected from the group consisting of a mono film, a multi-layer laminate film, a rigid sheet, and a woven or knitted net.
  • the polymeric material may be selected from the group consisting of polyethylenes and co-polymers of polyethylene, such as poly(ethylene-co-ethyl vinyl acetate), and polyvinyl chloride (PVC).
  • the polymeric material may be selected from the group consisting of polyethylene, polyvinyl chloride (PVC), polycarbonate (PC), polyethylene terephthalate (PET), and glass reinforced polyesters (GRP).
  • PVC polyvinyl chloride
  • PC polycarbonate
  • PET polyethylene terephthalate
  • GRP glass reinforced polyesters
  • the polymeric material may be selected from the group consisting of fibrous polyethylenes, polyamides, and polyesters.
  • a method of cultivating plants including the step of covering the plants with a plant protective cover of the first aspect of the invention.
  • plants cultivated using the plant protective cover of the first aspect of the invention are provided.
  • FIG. 1 is a graph depicting a typical transmittance spectrum of the photosynthetic active region of plants in general in comparison with that of two known polyethylene plant protective covers, namely a clear anti-fog anti-dust cover and a copper containing cover;
  • FIG. 2 is a graph depicting the selected transmittance spectrum of a theoretical ideal plant protective cover postulated by the applicant for optimising the photosynthetic characteristics of the light as well as modifying the non-desirable ultraviolet and infrared regions of the spectrum;
  • FIG. 3 is a graph depicting the transmittance spectrum of a known polyethylene plant protective cover, without any transmission spectrum modifiers, used in the horticultural industry;
  • FIG. 4 is a graph depicting the transmittance spectrum of another known polyethylene plant protective cover, without any transmission spectrum modifiers, produced from radiation pre-cross-linked linear low density polyethylene;
  • FIG. 5 is a graph depicting a transmittance spectrum indicating a reduced amount of transmittance of green and yellow wavelengths and a change in the ratio of transmittance of the blue to red wavelengths, by the inclusion of transmission spectrum modifiers in the plant protective cover in accordance with a first embodiment of the invention.
  • FIG. 6 is a graph depicting a transmittance spectrum indicating a reduced amount of transmitted green and yellow wavelengths and a change in the ratio of transmitted blue to red wavelengths, by the inclusion of transmission spectrum modifiers in the plant protective cover in accordance with a second embodiment of the invention, inclusive of both UV and IR spectrum modifiers.
  • FIG. 1 Shown in FIG. 1 is a graph depicting a transmittance spectrum of the photosynthetic active region of the light transmission spectrum and which would be ideal for optimal plant yield.
  • This graph is compared with two typical transmittance spectra of known polyethylene plant protective covers, namely a clear anti-fog anti-dust cover and a copper containing cover.
  • the graph shown in FIG. 2 depicts the light transmittance spectrum of a theoretical ideal plant protective cover postulated by the applicant.
  • Two peaks in the photosynthetic region minimises the transmittance of green and yellow wavelengths between the peaks at the red and the blue wavelengths. The red wavelength is the higher peak while the blue wavelength is the lower peak.
  • a plant protective cover according to a preferred embodiment of the invention is generally manufactured by the extrusion film blowing, as is known in the art of plastic film manufacture, of a translucent polymeric starting material such as radiation pre-crosslinked linear low-density polyethylene (LLDPE).
  • LLDPE radiation pre-crosslinked linear low-density polyethylene
  • the starting material is modified prior to film blowing by the inclusion of transmission spectrum modifiers and additives, so as to select the transmission spectrum in accordance with particular photosynthetic and photomorphogenic requirements of plants to be cultivated underneath the plant protective cover.
  • the transmission spectrum of the plant protective cover is also selected to minimise the transmission of the UV and IR portions of the spectrum.
  • the cover of the present invention optimises the transmittance spectrum in accordance with the photosynthetic and photomorphogenic requirements of plants in general. It will be appreciated that the photosynthetic and photomorphogenic requirements of different plant varieties may differ slightly from each other and the applicant foresees that through experimentation a profile could be prepared of the requirements of a particular plant variety, and the transmittance spectrum of the cover be further refined accordingly within the current parameters of the cover.
  • FIG. 3 Shown in FIG. 3 is a graph depicting the transmittance spectrum of a standard prior art polyethylene plant protective cover.
  • the graph in FIG. 4 depicts the light transmission spectrum of a polyethylene plant protective film, which was manufactured employing a radiation pre-cross linked feedstock linear low-density polyethylene.
  • the plant protective covers shown in FIG. 3 and FIG. 4 do not include any transmission spectrum modifiers. It follows from the graphs, that these covers have light transmittance spectra that are almost identical to that of similar prior art polyethylene plant protective covers.
  • FIG. 5 shows the transmission spectrum of the cover according to a first embodiment of the invention, and which is modified in the photosynthetic active region according to the general photosynthetic and photomorphogenic requirements of plants to be cultivated underneath the cover. From the graph in FIG. 5 , it is evident that it is possible to reduce the amount of transmittance of light of green and yellow wavelengths as well as to change the ratio of blue to red wavelengths by the inclusion of suitable spectrum modifying agents in the plant protective cover. For this film, no UV and IR spectrum modifiers were included.
  • a plant protective cover according to a second embodiment of the invention in the form of a photo-selective film was prepared as set out below.
  • table 1 the composition of the film, including pre-selected additives, is depicted:
  • a film with a thickness of 180 ⁇ m was made through a process of extrusion film blowing employing a single screw extruder for the manufacture of a mono-layer film.
  • the transmission spectrum of the plant protective cover manufactured in according to the example shown in Table 1 is presented in FIG. 6 . It will be noticed that the transmittance spectrum is similar to the theoretical optimal transmittance spectrum that was postulated by the applicant.
  • the plant protective cover in accordance with the second embodiment of the invention having a selected optimal transmission spectrum (such as that of FIG. 6 ) results in a cover that enhances plant growth and decreases plant stress, whilst inhibiting insect activity underneath the cover. This is achieved by maximising the light transmittance of the plant protective cover in the red and far-red wavelengths (see 5 in FIG. 2 ), eliminating the ultraviolet region (see 1 in FIG. 2 ), decreasing the transmitted green and yellow wavelengths, as well as changing the ratio of blue to red wavelengths transmitted to a 2:3 ratio (see 2 and 3 in FIG. 2 ).
  • Vegetative growth is optimised and plant quality enhanced by allowing the highest possible amount of red and far-red wavelengths to be transmitted (see 1 and 3 in FIG. 2 ). Cooling costs are also reduced by minimising the infrared transmittance through the cover (see 4 in FIG. 2 ).
  • the plant protective cover of the invention has excellent mechanical properties, as well as a particularly high environmental stress cracking resistance owing to the polymer selection and pre-crosslinking thereof.
  • the plant protective cover of the invention thus has both enhanced photosynthetic and excellent inherent film characteristics. It will be appreciated that these are features that positively impact on the economic potential of a plant protective cover according to the present invention.
  • the plant protective cover greatly enhances the production and quality of plants cultivated underneath the cover as a more favourable growing environment for plants cultivated underneath the cover is established.
  • the invention enables a grower of plants to customise the cover in accordance with the particular variety of plant cultivated underneath the cover. This is done by preparing a profile of the optimal photosynthetic and photomorphogenic requirements of a particular variety of plant to be cultivated underneath the plant protective cover and adjusting the transmittance characteristics of the cover to match the requirements of the plant, within the parameters of the present cover.
  • the adjustment of the transmittance characteristics of the cover is achieved by varying the amounts of additives depicted in Table 1 relative to each other.
  • Rose plants Rosa hybrida , cv. Grand Gala; a vigorously growing, red, long stemmed, thornless rose
  • Rosa hybrida cv. Grand Gala; a vigorously growing, red, long stemmed, thornless rose
  • This variety of rose has a straight and erect growth form.
  • the roses were two years old and fully productive when the study initiated.
  • the ‘Grand Gala’ rose is classified as follows:
  • the rose plants had two or more basal shoots and were multiple-stemmed.
  • the stems were harvested continuously, a method known as staggering (stagger harvesting), throughout the study period.
  • the developmental stage at harvesting varies with cultivar, season and distance to the market, but generally the stems are harvested at the tightest stage at which the flower will open in neat water.
  • the stems of yellow cultivars are harvested with the flower bud tighter than the pink cultivars, which is again harvested tighter than the flower buds of red cultivars. In the instances where the stems were harvested with the flower buds too tight, the flower will not open.
  • stems of the pink cultivars and especially the red cultivars must be harvested when at least one of the outer petals has started to unfold (Meyer et al, 1988, Pellett et al, 1998). Since ‘Grand Gala’ is a red cultivar the stems were harvested at the latter stage. The stems were harvested three times per day (6:00, 12:00 and 17:00). Whenever possible, stems were harvested in the early morning or late afternoon to prevent dehydration of the stems.
  • the bent stem technique was used during this study. In short, this technique entails the bending down of lateral stems to increase the number of leaves (foliage) available for the process of photosynthesis. These lateral stems that are bent down are stems of poor quality: thin and short stems with small or deformed buds. By using this technique, the aisles are filled with foliage and are not very easily distinguishable from the beds itself, giving an overall bushy appearance.
  • the exceptionally long stems of this particular cultivar were kept in an upright position while they were growing. They were supported by wire fastened to the wooden poles planted ⁇ 12 meters apart at either side of each bed. The wire was fastened at a height of 45 cm and again at a height of 90 cm from the soil surface. The stems (shoots) were guided periodically to an upright position. This practice reduces the breaking and bending of the long stem roses and thus retaining the quality of the stems. Suckers, originating from the rootstock, also called the understock, were removed and secondary buds were pinched of, leaving only the terminal bud to fully develop into a flower.
  • the blind shoots were removed in an early stage of shoot development, since allowing the development of non-marketable stems is too wasteful from a plant energy utilisation perspective.
  • Stems with bent necks were harvested and sold as low-grade stems.
  • Stems originating from the basal shoots also referred to as ‘water shoots’ or ‘renewal canes’, were also harvested for the local market.
  • the beds and aisles of the greenhouse were kept free of weeds, fallen leaves, petals and twigs, minimising the occurrence and spreading of diseases.
  • the dead and sick parts of the rose bushes were also removed for the same reason.
  • the greenhouse had a length of 100 m, a width of 50 m and a height of 5 m, covering a surface area of 5000 m 2 or 1 ⁇ 2 a hectare.
  • the beds of the greenhouse (72 beds in total) were 47 m long and 1 m wide and raised to a height of 0.40 m, with aisles of 0.40 m in between.
  • Each bed consisted of two rows of roses with a total of 556 rose plants per bed. There were a total number of 40000 rose plants in the greenhouse (8 plants.m ⁇ 2 of the greenhouse).
  • the control part of the greenhouse was covered with a 200 micron, UV protected polyethylene film (Triclear).
  • the growth medium was the soil of the setting itself of a sandy-loam texture.
  • the experimental part of the greenhouse was covered with the cover of the second embodiment of the invention as described above. Three roof strips of the green house were replaced with the cover of the invention, with measurements being taken only at the central portion, to minimise the impact of unmodified light from the sides.
  • a drip irrigation system was used to apply water and fertilise the plants simultaneously; a process called fertigation.
  • the fertigation system was completely automated: the timing and amount of irrigation water and fertiliser applied and the EC (electrical conductivity—amount of ions in solution) were thus continually monitored and kept constant. It had the advantage that the water and fertiliser were applied in specific quantities directly to the root zone of the plants.
  • the EC differed between the summer and winter periods; in summer it was set between 1.3 and 1.4 mS cm ⁇ 1 while in winter it was set between 1.6 and 1.7 mS cm ⁇ 1 . More irrigation cycles were applied in summer than in winter.
  • the water pH (water and fertiliser) was kept constant at 6.5.
  • the irrigation pipes were 2.5 cm wide plastic pipes with perforations (called drippers in this experiment) 30 cm apart, with no nozzles attached to it.
  • Each bed had one irrigation pipe, running in the middle of the bed and the whole length of the bed.
  • Each of the irrigation pipes had an irrigation capacity of 1 liter dripper ⁇ 1 hour ⁇ 1 except one of the side beds, which had an irrigation capacity of 1 ⁇ 2 a liter dripper ⁇ 1 hour ⁇ 1 owing to the capacity of its distributors.
  • the volume of water applied to the plants was kept at 1.2 l plant ⁇ 1 day ⁇ 1 since it was close to the maximum transpiration rate of a rose plant, being 1.5 l m ⁇ 2 day ⁇ 1 (in the summer).
  • Natural air movement was used to cool and ventilate the interior of the greenhouse.
  • the ventilation system comprised of six roof flaps that ran parallel with the length of the greenhouse and opened in a westerly direction.
  • the ventilation system was computerised using temperature, humidity and wind speed as the determining factors for the aperture size of the roof flaps.
  • the greenhouse had adjustable sidewalls, they were never opened for ventilation and cooling.
  • the cooling and ventilation system was not effective in lowering the air temperature of the greenhouse interior.
  • the total daily PPFD (mol m ⁇ 2 day ⁇ 1 ) was calculated while the day length as well as the irradiation hours were obtained from the South African Weather Bureau.
  • Irradiation levels (PPFD), air temperature and [CO 2 ] measured at 7 h 00, 12 h 00 and 15 h 30 as well as the calculated RH % and VPD are presented in Table 2.
  • PPFD measured at 12 h 00 and 15 h 30 is much higher than that in other studies e.g. 50-150 ⁇ mol m ⁇ 2 s ⁇ 1 (Blom-Zandstra et al., 1995) and 100-1200 ⁇ mol m ⁇ 2 s ⁇ 1 (Jiao et al., 1991).
  • the average temperatures during the day (18-28° C.) corresponds to the air temperature reported in previous studies (Hopper and Hammer, 1991; Mor and Halevy, 1984).
  • [CO 2 ] at 12 h 00 and 15 h 30 were in the range of the atmospheric [CO 2 ] of 350 ⁇ mol mol ⁇ 1 (Jiao et al., 1991; Taiz and Zeiger, 1991), while those at 7 h 00 were higher. This might probably be due to the closed roof vents, the nightly respiration of the plants and the minimal photosynthesis rate.
  • the average % RH values determined for the 7 h 00, 12 h 00 and 15 h 30 data were all much lower than the recommended value of 65% determined by Mortensen and Fjeld (1998) and 75% by Mortensen and Gisler ⁇ d (1999).
  • the average daily irradiation time was >9 hours and the daily PPFD ranged from 43-60 mol m ⁇ 2 day ⁇ 1 and the latter compares well with the values for a monthly average in summer at medium latitudes viz. 30-60 mol m ⁇ 2 day ⁇ 1 (Salisbury & Ross, 1992).
  • Seedlings and potted plants cultivated under the cover also showed substantial growth stimulated responses, in that both had superior foliage colour development (greening due to increased chlorophyl production) and the seedlings showed substantial increased root development. Furthermore, whilst the potted plants cultivated under the cover flowered five days later, the plants were vegetatively superior and had a relatively better colour development.
  • cover is not limited to any particular form, but could be produced in a form selected from the group consisting of inter alia a mono film, a multi-layer laminate film, a rigid sheet, and a woven or knitted net.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Soil Sciences (AREA)
  • Environmental Sciences (AREA)
  • Protection Of Plants (AREA)
  • Cultivation Of Plants (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Greenhouses (AREA)
US10/548,104 2003-03-06 2004-03-04 Plant protective cover Expired - Fee Related US7762019B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
ZA2002/9627 2003-03-06
ZA200209627 2003-03-06
PCT/IB2004/050199 WO2004077935A1 (en) 2003-03-06 2004-03-04 Plant protective cover

Publications (2)

Publication Number Publication Date
US20060254136A1 US20060254136A1 (en) 2006-11-16
US7762019B2 true US7762019B2 (en) 2010-07-27

Family

ID=32962885

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/548,104 Expired - Fee Related US7762019B2 (en) 2003-03-06 2004-03-04 Plant protective cover

Country Status (9)

Country Link
US (1) US7762019B2 (zh)
EP (1) EP1599085B1 (zh)
CN (1) CN1777359B (zh)
AP (1) AP2062A (zh)
AU (1) AU2004217928B2 (zh)
BR (1) BRPI0408139A (zh)
ES (1) ES2550535T3 (zh)
WO (1) WO2004077935A1 (zh)
ZA (1) ZA200507156B (zh)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013150565A (ja) * 2012-01-25 2013-08-08 Sumitomo Chemical Co Ltd ポリオレフィン系農業用フィルムおよび農園芸用施設
US20150173302A1 (en) * 2013-12-20 2015-06-25 Elwha Llc Reflective articles and methods for increasing photosynthesis
US10813298B2 (en) * 2016-06-24 2020-10-27 Universidad De Concepcion Two-color net for protecting fruit against damage caused by direct solar radiation and high temperatures
US11219170B2 (en) * 2017-12-20 2022-01-11 Berry Global, Inc. Shelters for plants

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7327923B2 (en) 2006-03-31 2008-02-05 3M Innovative Properties Company Spiral multilayer fibers
DK2042031T3 (da) * 2007-09-28 2010-05-31 Scheuten S A R L Væksthussystem
CN102352078A (zh) * 2011-08-25 2012-02-15 成都市新津事丰医疗器械有限公司 医用pvc避光色浆
CN102505808B (zh) * 2011-10-24 2013-09-18 濮阳市林业科学院 超薄轻载保温型日光温室后坡的建造方法
EP2703528A1 (en) * 2012-08-31 2014-03-05 baumhueter extrusion GmbH Cross-linked polyethylene fibre, its use and process for its manufacture
CN103396629B (zh) * 2013-07-15 2015-07-08 胡本巨 一种抑烟阻燃隔音pvc及其制备方法
BR112017012353A2 (pt) * 2014-12-12 2018-02-27 Sabic Global Technologies Bv filmes termoplásticos para aplicações de plasticultura
CR20160221A (es) * 2016-05-13 2016-06-28 Corporación Yanber Sa Sistema integrado para el control de plagas en banano, por medio de un dispositivo plastico y una camara biologica
CN109310053B (zh) * 2016-06-16 2022-06-07 索尼公司 信息处理设备，信息处理方法及计算机程序产品
WO2019197805A1 (en) * 2018-04-12 2019-10-17 British Polythene Limited Polymeric film
CN109628375A (zh) * 2018-12-27 2019-04-16 武汉伯远生物科技有限公司 通过优化培养皿吸收光谱消除培养皿凝水的方法及培养皿
CR20190421A (es) * 2019-09-09 2020-01-16 Olefinas S A Funda plástica para el control de residuos de banano por medio de una tecnología polimérica de tres capas de bloqueo de paso de insecticidas hacia la fruta
CN114868543A (zh) * 2022-05-30 2022-08-09 甘肃农业大学 一种绿光代替部分红蓝光增强黄瓜幼苗抗旱性的方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4134875A (en) 1978-03-17 1979-01-16 Alcudia Empresa Para La Industria Quimica, S.A. Polyolefin film for agricultural use
GB2057454A (en) 1979-08-27 1981-04-01 Yeda Res & Dev Polymeric compositions of matter for use in agriculture
US4423164A (en) 1981-02-04 1983-12-27 Rami Bar Polymeric films for use in agriculture
US4559381A (en) 1984-01-13 1985-12-17 Alcudia, Empresa Para La Indusrria Quimica, S.A. Polymeric covering materials for growing plants or crops
US4895904A (en) 1984-06-09 1990-01-23 Yael Allingham Plastic sheeting for greenhouse and the like
EP0761427A1 (en) 1995-08-28 1997-03-12 Sumitomo Chemical Company Limited Polyolefin resin covering film and method for raising plants
US5767179A (en) 1995-06-23 1998-06-16 Fuji Chemical Industry Co., Ltd. Lithium-aluminum hydroxide complex with condensed silicate
EP1178078A1 (en) 1994-06-27 2002-02-06 Ciba SC Holding AG Polyolefin or olefin copolymer films having improved light stability and pesticide resistance
EP1342748A1 (en) 2002-03-04 2003-09-10 Ciba SC Holding AG Synergistic combinations of UV Absorbers for pigmented polyolefins

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0732049B1 (en) * 1995-03-17 1998-05-06 Mitsui Toatsu Chemicals, Incorporated Covering material for plant growth control
CN1307070A (zh) * 2000-01-25 2001-08-08 中国科学院长春光学精密机械研究所 一种农用塑料棚膜

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4134875A (en) 1978-03-17 1979-01-16 Alcudia Empresa Para La Industria Quimica, S.A. Polyolefin film for agricultural use
GB2057454A (en) 1979-08-27 1981-04-01 Yeda Res & Dev Polymeric compositions of matter for use in agriculture
US4423164A (en) 1981-02-04 1983-12-27 Rami Bar Polymeric films for use in agriculture
US4559381A (en) 1984-01-13 1985-12-17 Alcudia, Empresa Para La Indusrria Quimica, S.A. Polymeric covering materials for growing plants or crops
US4895904A (en) 1984-06-09 1990-01-23 Yael Allingham Plastic sheeting for greenhouse and the like
EP1178078A1 (en) 1994-06-27 2002-02-06 Ciba SC Holding AG Polyolefin or olefin copolymer films having improved light stability and pesticide resistance
US5767179A (en) 1995-06-23 1998-06-16 Fuji Chemical Industry Co., Ltd. Lithium-aluminum hydroxide complex with condensed silicate
EP0761427A1 (en) 1995-08-28 1997-03-12 Sumitomo Chemical Company Limited Polyolefin resin covering film and method for raising plants
EP1342748A1 (en) 2002-03-04 2003-09-10 Ciba SC Holding AG Synergistic combinations of UV Absorbers for pigmented polyolefins
US20040030009A1 (en) * 2002-03-04 2004-02-12 Francois Gugumus Synergistic combinations of UV absorbers for pigmented polyolefins

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013150565A (ja) * 2012-01-25 2013-08-08 Sumitomo Chemical Co Ltd ポリオレフィン系農業用フィルムおよび農園芸用施設
US20150173302A1 (en) * 2013-12-20 2015-06-25 Elwha Llc Reflective articles and methods for increasing photosynthesis
US9320201B2 (en) * 2013-12-20 2016-04-26 Elwha Llc Reflective articles and methods for increasing photosynthesis
US10575476B2 (en) 2013-12-20 2020-03-03 Elwha Llc Reflective articles and methods for increasing photosynthesis
US10813298B2 (en) * 2016-06-24 2020-10-27 Universidad De Concepcion Two-color net for protecting fruit against damage caused by direct solar radiation and high temperatures
US11219170B2 (en) * 2017-12-20 2022-01-11 Berry Global, Inc. Shelters for plants

Also Published As

Publication number Publication date
AP2062A (en) 2009-10-28
ES2550535T3 (es) 2015-11-10
BRPI0408139A (pt) 2006-03-01
US20060254136A1 (en) 2006-11-16
AU2004217928A1 (en) 2004-09-16
CN1777359A (zh) 2006-05-24
AU2004217928B2 (en) 2010-06-10
AP2005003389A0 (en) 2005-09-30
WO2004077935A1 (en) 2004-09-16
EP1599085B1 (en) 2015-07-22
EP1599085A1 (en) 2005-11-30
CN1777359B (zh) 2010-04-28
ZA200507156B (en) 2006-04-26

Similar Documents

Publication Publication Date Title
ZA200507156B (en) Plant protective cover
Morgan et al. The effects of simulated daylight and shade-light on vegetative and reproductive growth in kiwifruit and grapevine
CN102726190A (zh) 一种红叶紫薇扦插育苗方法
CN102835234A (zh) 干旱沙区葡萄多抗砧木硬枝嫁接营养袋育苗方法
Jovicich et al. " Spanish" pepper trellis system and high plant density can increase fruit yield, fruit quality, and reduce labor in a hydroponic, passive-ventilated greenhouse
CN103404428B (zh) 福红大樱桃杂交培育方法
Vescera et al. Effects of three production systems on muskmelon yield and quality in New England
KR101030517B1 (ko) 황금먼나무의 무성번식방법
CN108834779B (zh) 一种培育日光温室越冬茬番茄高产株型的方法
CN107211717B (zh) 一种日光温室早春甜瓜-秋冬草莓种植方法
CN102907281A (zh) 薯类基苗越冬大棚及利用该大棚对薯类基苗越冬的方法
Särkkä et al. Effects of bending and harvesting height combinations on cut rose yield in a dense plantation with high intensity lighting
CN110754235A (zh) 西番莲大田高位嫁接及栽培方法
Wien et al. Use of high tunnels in the Northeastern USA: Adaptation to cold climates
CN112273209B (zh) 一种led作为补充光源的抱子甘蓝的栽培方法
Ramya Mol et al. Evaluation of potting mixtures and humidity conditions for rooting and establishment of plagiotropic branches of black pepper (Piper nigrum L.)
Lodhi et al. Low tunnel technology for vegetable crops in India
CN107853049B (zh) 一种柠檬树的季节性修剪方法及柠檬园
Laulina et al. Soil temperature variation for different plastic mulches for capsicum crop under greenhouse condition
Pisciotta et al. Table-Grape Cultivation in Soil-Less Systems: A Review. Horticulturae 2022, 8, 553
Nair et al. Influence of coloured shade nets and seasons on production and quality of cut foliage of leather leaf fern (Rumohra adiantiformis)
CN115715523B (zh) 一种滇中地区草莓脱毒种源快速构建与扩繁的方法
Polat* Environmental Requirements
Polat et al. Environmental Requirements and Site Selection
Singh et al. 16 Mulching

Legal Events

Date Code Title Description
AS Assignment

Owner name: NORTH-WEST UNIVERSITY, SOUTH AFRICA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:VAN RENSBURG, LEON;DU PLESSIS, TJAART ANDRIES;SEUTE, HORST;SIGNING DATES FROM 20051025 TO 20051031;REEL/FRAME:017997/0074

Owner name: NORTH-WEST UNIVERSITY, SOUTH AFRICA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:VAN RENSBURG, LEON;DU PLESSIS, TJAART ANDRIES;SEUTE, HORST;REEL/FRAME:017997/0074;SIGNING DATES FROM 20051025 TO 20051031

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552)

Year of fee payment: 8

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20220727